In the past few years, Internet piracy of music, movies and books caused losses of billions of dollars to content owners. “Content” as used in the present invention refers to “static” content, i.e. content that does not change from one view to another. Static content includes entertainment and publishing industry products such as music, movies, books, etc, distributable electronically in digital or analog formats. Specific examples include video (movie), audio (music, podcasts, audio books etc.), text, e-books, presentations and images. In contrast, “dynamic’ content (such as SW programs, computer games etc.) is interactive in nature and may change each time it is used according to the users' inputs.
The ease with which every Internet user can download almost any static content and use it without paying royalties to the content owner, is a major concern for music companies, production studios and book publishers. In order to fight this phenomenon, content owners try to take legal actions against users who download content illegally, conduct educational school campaigns and even try passing legislation that will close all file-sharing networks.
The addition of advertisements (“ads”) to static content files is known. US Patent Application 2004024727 to Bowman discloses a method and system for adding advertisements to peer-to-peer files through a network router. The system sits on the network router within a broadband provider and can change files being downloaded by customers of this provider. A major disadvantage of this solution is that it needs to be deployed within all broadband providers worldwide to enable all users to view the content with advertisements, this being patently unfeasible.
US Patent Application 2002099798 to Fedorovsky et al describes the adding of advertisements to files in a client-server environment. When the client requests to download content, the server sends the content plus some personalized ads. The ads are bundled with the content during the download and are not stored separately on the user's device. This solution does not work in a file-sharing environment, which has a completely different architecture. Moreover, the ads are added to the file during the download process and not in real time, when the content is being viewed.
Patent Application WO2004036384 to Huber et al describes the addition of advertising in a broadcasting environment (streaming). Streaming solutions cannot enable users to collect content, to view content offline or to share content through file-sharing networks and therefore cannot work in a download environment.
Patent Application WO03065219 to Berkson et al describes a method and system for delivering “free” media content via a network or the Internet, whereby media content files are bundled with advertisements. The bundling of ads with the content has several drawbacks:    1) Each file is different from the others (which have different ads) and thus it is impossible to enjoy the benefits of file-sharing, where the same file can be downloaded from different users and save download time.    2) Since the user has all the information and since all the ads are held separately, it is relatively easy for hackers to build a player that will remove the ads from the content. Furthermore, it is impossible to implement territorial rights management, as users can download the whole content from their peers.    3) The personalization capabilities are very limited—as long as an ad has not expired, it will not change even if a completely different user will view it.    4) Advertisers want to limit the total amount of times a certain ad is being viewed or the total number of viewers who view the ad (in order to control their expenditure). This cannot be done in this invention.
Since file-sharing is one of the best distribution tools ever invented, it would be advantageous to provide content owners with a way to leverage the file-sharing success and make a profit of it, rather than closing the file-sharing networks. Furthermore, when millions of people can share the same content file, the need arises to personalize the content to each user while used, with the content file itself being unchanged.